Dividing head or rotary indexer?

[3strucking]

I have a horizontal rotary table but I need to be able to hold work vertical. I also need a chuck so what would I be better off with? A BS style dividing head with chuck or a H/V rotary indexer?

 

[Bob Korves]

Well, a horizontal RT does hold work vertically. Assuming you actually want to hold the RT vertical to make a cut in a horizontal plane, you can make a custom bracket to hold your horizontal RT vertical. Don't bother attempting it if you cannot do a good enough job at it so it is properly square to the table and sturdy enough for the job. Edit: the horizontal set vertically will take up a LOT of headroom on the mill. Make sure your machine has the height from table to spindle to accommodate both the setup and the work...

 

[pontiac428]

I reckon a RT and a dividing head are two different tools, in spite of some of the ways that they may used to achieve the same results. I own both, but my RT is horizontal only, so I do vertical RT tasks in my B&S type dividing head. What the dividing head does best is indexing, dividing circles into sectors with excellent precision. While the same can be done with a RT, index plates are precise and easy to work with. Trying to divide a circle into, say, 7 parts would have you trying to accurately dial degrees-minutes-seconds off of a crib sheet, where on the dividing head it's a no-brainer. The RT would usually be a better choice than the dividing head at cutting radii on the mill as one example. Two different tools, two different things to sneak past the wife, but having both would give you more capability than only having one or the other.

 

[Janderso]

Crib sheet?
Please explain Mr. Pontiac

 

[Choiliefan]

If you are doing simple indexing, the HV rotary indexer would be my choice.
It has a much lower profile relative to the spindle axis and if threaded nose like some of the Hardinge you can avail not only 5C collets but face plates and chucks.

 

[pontiac428]

Just referred to the simplicity of dialing 7 divisions on an indexing plate (40x7 holes per rev, count 40 holes per step) vs. having to set up the task with a sheet of notes to accomplish the same thing on a rotary table: Step 1= 51.42857 degrees, step 2= 102.85714 degrees, step 3= 154.28571 degrees, so on.

It's good practice to use a crib sheet to plot your work, but it is also very tedious when simpler methods exist. There's a reason I chose the low prime 7 for an example, rather than 6, since 6 goes into 360 a geometrically elegant 60 times. Numbers that divide evenly like 3, 4, 6 kinda ruin my argument for one over the other.

 

[3strucking]

Thanks for the help.

 

[Illinoyance]

When I was making some barrel cams I opted for the RT. I had a printout of 720 sets of angular position and X position. I knew there would be interruptions during the job. By using the RT I could check on the last angle dialed in. With a dividing head there would be no way to figure out "where the hell was I".

 

[pontiac428]

With a dividing head there would be no way to figure out "where the hell was I".

Which is why sector fingers are used with dividing plates. They are essentially physical bookmarks for knowing where the heck you was.

 

[3strucking]

Will a dividing head do something a rotary indexer cant? I am really torn between the two styles.